Early Jurassic Caenogastropoda and Architectibranchia from the Neuquén Basin, Argentina

Abstract

Early Jurassic marine gastropods are well represented in Argentina by three major taxa: Vetigastropoda, Caenogastropoda and Architectibranchia (=Opisthobranchia). The present paper aims at the description of six new caenogastropod species and one new architectibranch species from the Early Jurassic marine deposits of the Neuquén Basin, namely Procerithium subimbricatum n. sp., Microschiza weaveri n. sp., Naricopsina aequabilis n. sp., Naricopsina ballentae n. sp., Pictavia rothi n. sp., Oonia acuta n. sp., and Cylindrobullina brevispira n. sp. Seven other caenogastropods are reported for the first time in the area, including Cryptaulax redelii Ferrari, Procerithium nulloi (Ferrari), Rhabdocolpus patagoniensis (Ferrari), Rhabdocolpus? sp., Pseudomelania feruglioi Ferrari, Pseudomelania aff. baugieriana (d’Orbigny), and Anulifera chubutensis Ferrari, extending their palaeobiogeographical distribution to the Andean region of Argentina during the Early Jurassic. Caenogastropods such as Globularia catanlilensis (Weaver) and Microschiza? americana (Möricke), and the architectibranch species Striactaeonina transatlantica (Behrendsen) and Cylindrobullina ovata (Behrendsen) are redescribed and discussed based on new specimens from the type and other localities. The new fossils described here expand the known diversity of the gastropod faunas in the Early Jurassic of Argentina and contribute to the paleontological knowledge of the group in the Mesozoic of South America.